This seems very similar (although not identical) to the problem I have and posted a response about here:https://rog.asus.com/forum/showthread.php?107321-asus-rog-strix-z390-f-gaming-1-long-beep-followed-by-3-short-beepsEDIT:Having noticed the date of...
I have ther same problem but different main board:Asus Maximus Hero XI z390i9900k32Gb (4x8) Corsair RAMZotac GTX 2080 GTI AMPVarious SSDOne beep followed by 3 short on boot SOMETIMES.I get this probably once in 4 or 5 boots. If I leave it the system ...